Place pierogies, onion, red pepper, bacon, salt and pepper in large freezer bag.
Add the cream of mushroom soup and evaporated milk to a bowl. Whisk together the two ingredients until well combined.
Pour the sauce over the other ingredients in the freezer bag. Squish the bag with your hands to combine the sauce and other ingredients. Remove excess air from the bag and seal it.
Put the shredded cheese in medium freezer bag and seal.
Staple the bag of cheese to large bag above the seal and place in the freezer.
Cooking Instructions:
Thaw.
Preheat the oven to 350° and grease a casserole dish with nonstick cooking spray.
Dump the ingredients in the larger freezer bag into the casserole dish. Top with the shredded cheese.
Bake the casserole for 45 minutes, until the sauce is bubbly and the cheese on top is melted.
Slow Cooker Instructions:
Thaw.
Dump the large bag contents into a Crock Pot and top with cheese.
Cook on low for 4 hours or on high for 3 hours.
Recipe Notes
You can make this casserole vegetarian by using imitation bacon bits or omitting the bacon from the recipe.